Gwyneth Paltrow's Star-Studded 40th Birthday Party: All the Details!

Quiet Upper East Side Italian eatery Elio's was the place to be in New York on Friday night. The reason? That's where Gwyneth Paltrow feted her 40th birthday, with a little help from some very famous friends.

Around 7:15 p.m., an eyewitness tells Us Weekly guests like Steven Spielberg, Kate Capshaw and Gwyneth's mom, Blythe Danner, started showing up. The birthday girl -- clad in a chic black blouse with white trim, arrived a half-hour later, followed by Jessica Seinfeld, Chelsea Handler and Kristen Wiig.

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Ethan Hawke pulled up around half past 8, while Paltrow's BFF Beyonce arrived fashionably late at 9:30. Also in attendance? Jake Gyllenhaal, Christy Turlington, The Beastie Boys' Mike D, Cameron Diaz and Gwyneth's hubby Chris Martin.

Once inside, the group ate, drank, and mingled to a low-key, lounge-like piano soundtrack. (Paltrow and her pals ate chocolate cake for dessert, a source tells Us.)

Prior to heading to her party, another insider reveals the mom to Apple and Moses got ready for her big night with pal Diaz, also 40. (Celeb hair pro Josue Perez styled both of the blonde stunners' 'dos.)

"They are really fun and close. They were having a great time getting ready for the party," the insider shares. "There were lots of laughs."

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Earlier this week, Paltrow opened up to reporters at Tracy Anderson's Pregnancy Project event about her latest milestone. (She officially turned 40 on September 27).

"I was really worried about it, leading up to the day, but now I feel really happy and content with my life," the Academy Award winner shared. "I'm excited to move into the next phase. It's much more exciting than I thought it would be."

This article originally appeared on Usmagazine.com: Gwyneth Paltrow's Star-Studded 40th Birthday Party: All the Details!

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